Traditionally, a door lock has been able to adopt a locked mode and an unlocked mode, typically by turning a key in the lock. More recently, locks have become more sophisticated and have multiple modes. These modes may include a “passage mode” by which is meant that the door can be opened from the inside and the outside simply by operating the door handle, a “safety mode” by which is meant that the door is locked from one side (typically the outside) but can be opened from the inside by turning the handle, and a “secure mode” by which is meant that the door is locked from both the inside and the outside.
It is well-known to provide a “safety mode” mechanism that enables the door to be operated from the inside but not from the outside. This type of mechanism is commonly used on external doors and interior doors, such as, but not limited to, school room doors, bathroom doors and the like. Such doors often have an indicator on the outside of a door to let the person on the outside of the door know if the door is locked. A very well-known example is the public toilet door lock which has an “engaged/vacant” indicator which is operated from the inside of the door and upon locking of the door.
In many instances, such as, but not limited to, in school classrooms, it is beneficial to have a lock mechanism which can be locked or unlocked from the outside lever or handle. However, for safety reasons, the inside lever or handle must always be free to open the door for immediate exit, whether the outside handle is locked or unlocked. It is also beneficial to have a lock mechanism which can be locked from the inside handle, while still allowing the inside handle to be free to open the door for immediate exit. However, because the key on either side rotates 360-degrees to lock or unlock the mechanism and as the inside handle must remain free, it is difficult for a user positioned proximate the inside handle to know if the mechanism is locked or unlocked. This can prove disastrous in instances in which there is danger outside of the classroom and the occupants of the classroom want to confirm that the lock mechanism is in the locked position.
It would, therefore, be beneficial to provide a door lock indicator which can be used by occupants in the interior of the classroom or other space to confirm if the lock mechanism is in the locked or unlocked position, thereby allowing the occupants to know if the door is secure or not secure.